Trevor Fraser-University of Manitoba's:
Liquid pig manure has both nitrogen and phosphorus in it.
The nitrogen tends to be more in the ammonia form which is readily available to plants where as something like a solid pig manure or a solid dairy manure the form of nitrogen would be mostly in the organic form and that organic form needs to mineralize before it becomes available.
We found that those liquid pig manures, they tend to be very quickly available for plants and the plants are readily able to pick up that ammonia.
Where as the solid manures, they take a much longer time before that nitrogen becomes available.
We saw that it took up to six years before we started to see nitrogen becoming available from yearly applications of solid manures.
We also found that those were very effective at increasing soil phosphorus levels but actually, even though we're importing lots and lots of phosphorus with those solid manures, the effect it had on soil P was lower than the effect that liquid manures had on soil P.
Fraser suggests when planning manure application they need to consider the type of manure, the form of manure whether it's liquid or solid and the cropping system to which it's being applied.
Source: Farmscape